package operators;// operators/DoubleEquivalence.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.

public class DoubleEquivalence {
    static void show(String desc, Double n1, Double n2) {
        System.out.println(desc + ":");
        System.out.printf(
                "%e==%e %b %b%n", n1, n2, n1 == n2, n1.equals(n2));
    }

    @SuppressWarnings("deprecation")
    public static void test(double x1, double x2) {
        // x1.equals(x2) // Won't compile
        System.out.printf("%e==%e %b%n", x1, x2, x1 == x2);
        Double d1 = x1;
        Double d2 = x2;
        show("Automatic", d1, d2);
        Double r1 = new Double(x1);
        Double r2 = new Double(x2);
        show("new Double()", r1, r2);
        Double v1 = Double.valueOf(x1);
        Double v2 = Double.valueOf(x2);
        show("Double.valueOf()", v1, v2);
    }

    public static void main(String[] args) {
        test(0, Double.MIN_VALUE);
        System.out.println("------------------------");
        test(Double.MAX_VALUE,
                Double.MAX_VALUE - Double.MIN_VALUE * 1_000_000);
    }
}
/* Output:
0.000000e+00==4.900000e-324 false
Automatic:
0.000000e+00==4.900000e-324 false false
new Double():
0.000000e+00==4.900000e-324 false false
Double.valueOf():
0.000000e+00==4.900000e-324 false false
------------------------
1.797693e+308==1.797693e+308 true
Automatic:
1.797693e+308==1.797693e+308 false true
new Double():
1.797693e+308==1.797693e+308 false true
Double.valueOf():
1.797693e+308==1.797693e+308 false true
*/
